For example, Patent Document 1 discloses a vapor fuel processing apparatus equipped to a vehicle. The vapor fuel processing apparatus includes a tank sealing valve equipped with a two-stage switching valve. A vapor fuel processing apparatus is configured to cause a canister to adsorb and hold vapor fuel, which is produced in a fuel tank. The vapor fuel processing apparatus is further configured to draw the vapor fuel, which is held in the canister, into an intake passage of an internal combustion engine.
The tank sealing valve opens and closes a vapor fuel passage, which is for drawing vapor fuel produced in the fuel tank, into the canister. The tank sealing valve may include a solenoid valve and a two-stage switching valve. The solenoid valve opens and closes the vapor fuel passage. The two-stage switching valve switches a flow quantity of fluid, which flows from the fuel tank toward the canister, in two stages including a large opening state and a small opening state, when the vapor fuel passage is open. In Patent Document 1, the second valve element 70 may be equivalent to a valve element of a two-stage switching valve. According to the two-stage switching valve of Patent Document 1, the second valve element 70 is not guided in a movable direction, and therefore, a seated portion of the second valve element 70 onto the second valve seat 17 may vary. Consequently, a sealing performance of the second valve element 70 may vary as time elapses.